Disappearing Arctic lakes could be disastrous to migratory birds

LOS ANGELES - Global warming appears to be causing lakes to
disappear in the Arctic regions, which could be disastrous for
migratory birds, a UCLA- headed team of researchers reported in the
magazine Science Thursday.

If the pattern continues, it could also wreak havoc on the
weather, said Laurence Smith, the article's lead author and
associate professor of geography at UCLA.

"In the Arctic these lakes are the dominant feature of the
landscape," he said. "The plant and animal life depends on them as
do native fishermen. The loss of these lakes would be an ecological
disaster."

Smith and his associates, including researchers from the State
University of New York in Syracuse and the University of Alaska in
Fairbanks, tracked changes in more than 10,000 large lakes by
comparing early satellite imagery taken across about 200,000 square
miles of Siberian wilderness and recent satellite data.

Between 1973 and 1998, about 125 lakes vanished entirely and
became covered with vegetation. Lakes of more than 100 acres
decreased in size by an average of 11 percent. The total surface
area of the lakes shrank by about 6 percent.

On the surface, the findings seem to conflict with past research
that showed that Arctic warming resulted in more and bigger lakes.
But Smith said global warming could be melting the permafrost,
causing lake water to seep into the ground.

"Most of these lakes are laying on top of permanently frozen
ground, a surface that prevents lake water from draining into the
ground," Smith said. "We think that climate warming is thawing the
permafrost. When that occurs, it's like pulling the plug out of a
bathtub. There's nothing to prevent lake water from percolating
through the soil to aquifers below."

Scientists focus on Arctic weather patterns because they change
faster than elsewhere. Arctic lakes are of particular concern
because they serve as a summer habitat for many migratory
birds.

"If they were to disappear, it would be disastrous for migrating
birds," Smith said. "The Arctic lakes and wetlands are widely used
as summertime habitat for migratory birds and for many species they
are critically important for feeding their young."

Further research is required to determine what effect shrinking
Arctic lakes will have on the weather.

"We haven't measured climate changes as a result of the lakes
disappearing, but we expect that the area would potentially enjoy
less precipitation if the lakes continue to decline because lakes
provide a source of evaporation, which creates clouds and rain in
other places," he said.